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$502+ Cheap flights from London (LON) to Seattle (SEA)

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 10/15. Fares are subject to change and may not be available on all flights or dates of travel.
LON — SEA
oct. 15 — oct. 221
mié. 10/15
mié. 10/22
1 adult, Economy
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Cheapflights Tip: The best prices from London to Seattle/Tacoma Intl are usually found in January or February, booked 90 days in advance, depart on a Wednesday or Monday and return on a Tuesday

Cheap flight deals from London to Seattle

Discover tips and strategies to find the most affordable flight options for your journey from London (LON) to Seattle (SEA). Learn about various techniques such as flexible date searches, comparing prices across and setting up price alerts. Use these methods to find the cheapest flights available for your travel needs. Data last updated septiembre 15, 2025.

Round-trip from

$603
(Trip.com)

One-way from

$502
(Kiwi.com)

Popular in

July

Cheapest in

January

Average price

$677

Good round-trip deal

$688 or less

Good one-way deal

$736 or less
From London (LON) to Seattle/Tacoma Intl
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One-way flight from London (LON) to Seattle/Tacoma Intl
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Highest demand for flights based on searches. 13% potential increase in price ($113 potential increase over avg. RT price).
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Cheapest flight prices on average. 2% potential price decrease ($17 potential savings vs. average RT price).
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Average for round-trip flights in September 2025
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Price to beat on a round-trip flight from London (LON) to Seattle/Tacoma Intl.
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Price to beat on a one-way flight from London (LON) to Seattle/Tacoma Intl.
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Find flight deals from London to Seattle

Cheapest flights from London to Seattle
Explore the most affordable flight options available from London to Seattle. Find the lowest fares from popular airlines and budget airlines, with prices last updated on septiembre 15, 2025.

This SmartFares deal was found by Cheapflights users on 9/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure SmartFares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 9/227:45 pmLHR - SEA
1 stop23h 30mVirgin Atlantic
lun. 10/65:35 pmSEA - LHR
Nonstop9h 45mVirgin Atlantic
Deal found 9/14$603
This Air Canada deal was found by Cheapflights users on 9/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 10/86:30 amLHR - SEA
2 stops15h 46mMultiple Airlines
mar. 10/1410:00 amSEA - LHR
2 stops15h 35mMultiple Airlines
Deal found 9/13$605
This FlightHub deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure FlightHub is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 11/512:15 pmLHR - SEA
1 stop12h 45mIcelandair
dom. 3/153:35 pmSEA - LHR
1 stop12h 15mIcelandair
Deal found 9/15$606
This ChecknFly deal was found by Cheapflights users on 9/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure ChecknFly is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 10/17:05 pmLHR - SEA
2 stops26h 54mFinnair
dom. 11/1612:59 amSEA - LHR
1 stop23h 16mFinnair
Deal found 9/14$607
This Kiwi.com deal was found by Cheapflights users on 9/13. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 9/227:30 pmLHR - SEA
2 stops33h 12mAustrian Airlines
lun. 10/67:00 amSEA - LHR
1 stop15h 20mAustrian Airlines
Deal found 9/13$608
This Kiwi.com deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 11/35:20 pmLGW - SEA
2 stops49h 15mMultiple Airlines
dom. 11/169:34 pmSEA - LGW
1 stop24h 26mMultiple Airlines
Deal found 9/15$610
This TravelUp deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure TravelUp is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 10/176:55 amLHR - SEA
1 stop18h 04mMultiple Airlines
lun. 10/205:30 amSEA - LHR
1 stop23h 50mMultiple Airlines
Deal found 9/15$610
This United Airlines deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
sáb. 11/18:30 amLHR - SEA
2 stops19h 21mUnited Airlines
jue. 11/69:04 amSEA - LHR
2 stops18h 01mUnited Airlines
Deal found 9/15$611
This oojo deal was found by Cheapflights users on 9/14. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 9/293:40 pmLGW - SEA
1 stop13h 00mIcelandair
lun. 10/67:00 pmSEA - LGW
1 stop11h 35mIcelandair
Deal found 9/14$612
This The Travel House deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure The Travel House is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
vie. 10/316:00 amLHR - SEA
2 stops23h 45mSWISS
sáb. 11/810:53 amSEA - LHR
1 stop13h 02mSWISS
Deal found 9/15$612
This Cheapflightsfares deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
lun. 11/36:40 pmLGW - SEA
2 stops36h 05mSWISS
dom. 11/162:40 pmSEA - LGW
2 stops19h 10mSWISS
Deal found 9/15$613
This Air Canada deal was found by Cheapflights users on 9/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Air Canada is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
mié. 10/158:40 amLHR - SEA
2 stops17h 56mAir Canada
mié. 10/222:55 pmSEA - LHR
1 stop14h 25mAir Canada
Deal found 9/15$613

Cheapflights Fare Finder

 
Customize your flight search to find flights from London to Seattle that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated septiembre 15, 2025.
Use the filters below to find and compare flights from London to Seattle that are best for you.

Fly from

London

Fly to

Seattle

Route

Depart

Return

Price

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

jue. 9/25

6:30 am-2:16 pm

2 stops15h 46m

Seattle/Tacoma Intl

mar. 9/30

11:10 am-11:45 am

2 stops16h 35m

$605

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

jue. 11/6

7:30 am-6:10 pm

2 stops18h 40m

Seattle/Tacoma Intl

jue. 11/13

7:13 pm-9:20 pm

2 stops18h 07m

$611

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

dom. 11/2

11:55 am-5:00 pm

1 stop13h 05m

Seattle/Tacoma Intl

mar. 3/31

3:45 pm-2:40 pm

1 stop14h 55m

$619

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

mié. 11/5

11:55 am-5:00 pm

1 stop13h 05m

Seattle/Tacoma Intl

mar. 3/31

7:00 pm-2:40 pm

1 stop11h 40m

$619

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

lun. 11/3

11:55 am-5:00 pm

1 stop13h 05m

Seattle/Tacoma Intl

mié. 4/1

7:00 pm-2:40 pm

1 stop11h 40m

$619

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

dom. 11/2

11:55 am-5:00 pm

1 stop13h 05m

Seattle/Tacoma Intl

jue. 4/2

7:00 pm-2:40 pm

1 stop11h 40m

$619

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

lun. 10/13

6:30 am-11:55 am

1 stop13h 25m

Seattle/Tacoma Intl

lun. 10/20

1:57 pm-11:45 am

1 stop13h 48m

$620

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

lun. 10/6

6:30 am-2:16 pm

2 stops15h 46m

Seattle/Tacoma Intl

lun. 10/27

3:40 pm-11:50 am

1 stop13h 10m

$620

LondonSeattle

LHR - SEA

LHRSEA

London Heathrow

sáb. 10/18

6:30 am-11:55 am

1 stop13h 25m

Seattle/Tacoma Intl

mié. 10/22

8:30 am-11:25 am

2 stops18h 55m

$620

LondonSeattle

LGW - SEA

LGWSEA

London Gatwick

sáb. 11/1

11:55 am-6:00 pm

1 stop13h 05m

Seattle/Tacoma Intl

mié. 3/11

3:35 pm-10:55 am

1 stop12h 20m

$620

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/15

Showing 1-10 of 60 results
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The best insider tips for London to Seattle flights

Snippets provided in this section are AI-generated based on a summarization of Cheapflights-commissioned articles. The articles are presented as-is, for general informational purposes only, and may not be up-to-date. The opinions contained in the articles are original to the author and reflect their authentic experience, which may vary significantly from the experience of others.
Cheapflights partnered with top experts to bring you the best recommendations for your London to Seattle trip
Airports
LHR

For a smooth departure from Heathrow, ensure all liquids are in one small bag to avoid lengthy security checks.

Read more about LHRby Ramsey Qubein
SEA

Use the Link light rail from SEA to downtown Seattle for an affordable, 40-minute journey with ample luggage space.

Read more about SEAby Brandon Schultz
Our travel experts
Ramsey Qubein

Ramsey Qubein

Expert on LHR

Ramsey Qubein

Ramsey Qubein

An avid traveler and aviation expert who has visited 173 countries, all 50 states and seven continents, Ramsey Qubein flies nearly 400,000 miles a year. As a North Carolina-based freelance journalist for publications including Conde Nast Traveler, Forbes, USA Today and Bloomberg among others, he explores the latest trends in aviation, hospitality, cruises and business.

Read more
Brandon Schultz

Brandon Schultz

Expert on SEA

Brandon Schultz

Brandon Schultz

Brandon Schultz is an award-winning food and travel writer based in New York City. His work has appeared in Forbes, AAA, Thrillist, Travel + Leisure, and The Daily Meal, among many others, and he is the author of 6 books, including 3 cookbooks.

Read more

Best time to book a flight from London to Seattle

Have a flexible travel schedule? Discover the best time to fly to Seattle from London with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from London to Seattle

How far ahead should I book a flight from London to Seattle?

Use this chart to determine the optimal time to book a round-trip flight from London to Seattle. Price data was last updated on September 12, 2025.

To ensure you get the cheapest price possible for a flight from London to Seattle, you should look to book at least 90 days in advance of your intended travel date. The price of your flight may increase if you delay and leave booking until a week or so before departure.

What is the cheapest month to book a flight from London to Seattle?

Currently, January is the cheapest month in which you can book a flight from London to Seattle (average of $238). Flying from London to Seattle in June is currently the most expensive (average of $387). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from LON to SEA?

Find hourly flight availability from London to Seattle. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated septiembre 15, 2025.

One of the essential ways to save on airfare from London to Seattle is to remain as flexible as possible. Flights that are in the evening tend to be the most expensive. A flight at noon could potentially save you up to 2% on airfare.

What is the cheapest day to fly from London to Seattle?

Use this chart to determine the cheapest time to fly round-trip from London to Seattle. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their London to Seattle flight should consider departing on Monday evenings when fares are most often at their lowest. Monday mornings flights should be avoided if possible as fares are typically the most expensive at this time.

Weekly flight availability from London to Seattle

Explore weekly flight availability from London to Seattle. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated septiembre 15, 2025.

The most flights from LON to SEA are scheduled on a Monday (21 on average). You will have fewer flight options on Tuesday, which is when the least amount of flights are scheduled (15 on average).

How much does it cost to fly round-trip from London to Seattle?

What’s the top layover airport for flights from London to Seattle?

Share of 1-stop round-trip flights from London to Seattle chosen by Cheapflights users in the past 12 months, using the same layover each way.

Reykjavik (KEF) – chosen by Cheapflights users on 67% of 1-stop itineraries from London to Seattle on Cheapflights.

What’s the cheapest layover airport for flights from London to Seattle?

Average round-trip fare for 1-stop flights from London to Seattle, chosen by Cheapflights users in the past 12 months, with the same layover each way.

Reykjavik (KEF) is the most affordable 1-stop option, with an average round-trip price of $596.

What’s the fastest layover option from London to Seattle?

Shortest average travel time for 1-stop one-way flights from London to Seattle, based on itineraries clicked by Cheapflights users over the past 12 months, grouped by layover airport.

Flights via Denver (DEN) have the shortest average one-way travel time for 1-stop routes: 14h 24m.

Which airport typically offers the quickest layover for flights from London to Seattle?

Average layover duration for 1-stop one-way flights from London to Seattle, chosen by Cheapflights users in the last 12 months, grouped by stopover airport.

Flights via Denver (DEN) offer the fastest connection on this route, with an average layover time of 1h 25m.

Reviews of airlines servicing Seattle

Get insights into the airlines that provide service to Seattle. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Seattle. Reviews last updated septiembre 15, 2025.
See what other customers who have flown with Delta, Virgin Atlantic, and Icelandair from London to Seattle have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
8.0
Very good
7,954 reviews

Crew

8.5

Comfort

7.9

Food

7.3

Entertainment

7.9

Overall

8.0

Boarding

8.2

Reviews

1 / 20
6.0
Good

Morgan Rae,Aug 2025

BRU - JFK

Typically I choose delta because they do a great job but this time the flight attendant in my zone was very rude and didnt offer the same treatment as she did to others
Delta
8.0
Very good
7,954 reviews
Delta
8.0
Very good
7,954 reviews

Crew

8.5

Comfort

7.9

Food

7.3

Entertainment

7.9

Overall

8.0

Boarding

8.2

Reviews

1 / 20
6.0
Good

Morgan Rae,Aug 2025

BRU - JFK

Typically I choose delta because they do a great job but this time the flight attendant in my zone was very rude and didnt offer the same treatment as she did to others
Virgin Atlantic
7.4
Good
664 reviews
Delta
8.0
Very good
7,954 reviews

Crew

8.5

Comfort

7.9

Food

7.3

Entertainment

7.9

Overall

8.0

Boarding

8.2

Reviews

1 / 20
6.0
Good

Morgan Rae,Aug 2025

BRU - JFK

Typically I choose delta because they do a great job but this time the flight attendant in my zone was very rude and didnt offer the same treatment as she did to others
Icelandair
7.0
Good
544 reviews
Delta
8.0
Very good
7,954 reviews

Crew

8.5

Comfort

7.9

Food

7.3

Entertainment

7.9

Overall

8.0

Boarding

8.2

Reviews

1 / 20
6.0
Good

Morgan Rae,Aug 2025

BRU - JFK

Typically I choose delta because they do a great job but this time the flight attendant in my zone was very rude and didnt offer the same treatment as she did to others
Iberia
7.0
Good
2,924 reviews
Delta
8.0
Very good
7,954 reviews

Crew

8.5

Comfort

7.9

Food

7.3

Entertainment

7.9

Overall

8.0

Boarding

8.2

Reviews

1 / 20
6.0
Good

Morgan Rae,Aug 2025

BRU - JFK

Typically I choose delta because they do a great job but this time the flight attendant in my zone was very rude and didnt offer the same treatment as she did to others
British Airways
6.7
Okay
7,361 reviews
Delta
8.0
Very good
7,954 reviews

Crew

8.5

Comfort

7.9

Food

7.3

Entertainment

7.9

Overall

8.0

Boarding

8.2

Reviews

1 / 20
6.0
Good

Morgan Rae,Aug 2025

BRU - JFK

Typically I choose delta because they do a great job but this time the flight attendant in my zone was very rude and didnt offer the same treatment as she did to others

Related info for your journey

Find useful and relevant information for your journey from London to Seattle. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly into for flights to Seattle from London?

    Seattle/Tacoma Intl (SEA), located 11.4 mi from the city center, is the airport you fly into when you book flights from London to Seattle. 5 airlines have flights to Seattle/Tacoma Intl from London on a regular basis. Booking flights from London to Seattle/Tacoma Intl should not be difficult; the airport handles an average of 20 inbound flights from London per day.

  • How long is the flight from London to Seattle?

    For as low as $619, United Airlines can have you in Seattle from London in 13h 05m. The distance from London to Seattle is about 4807 mi. Both multi-stop and nonstop flights can be found to your destination and back.

  • What are the cheapest airlines flying from London to Seattle round-trip?

    Cheapflights users have booked flights from London to Seattle round-trip from $402. Other airlines that can offer you cheap pricing are British Airways, from $560, and Virgin Atlantic, from $594. Icelandair is currently priced 45% below the average price you’ll pay for this route.

  • What are the cheapest airlines to fly from London to Seattle one-way?

    One-way options have recently been found by users for as low as $524 on Aer Lingus. Other airlines that offer cheap prices include British Airways from $525 and American Airlines from $529 one-way.

  • What are the most popular routes from London to Seattle?

    Most travelers choose London Heathrow - Seattle/Tacoma Intl, London Gatwick - Seattle/Tacoma Intl or London City - Seattle/Tacoma Intl when deciding on the best route from London to Seattle.

  • What are the most reliable airlines from London to Seattle?

    The top 3 most reliable airlines when flying from London to Seattle are Scandinavian Airlines (93%), KLM (89%) and Air France (89%).

  • What are the cheapest flights from London to Seattle?

    While on average a flight from London to Seattle is generally $2,282, our data shows the cheapest flight currently is $627. When looking at the most popular route, (London Heathrow - Seattle/Tacoma Intl), you can expect to pay $513 for that flight.

  • Can I find deals for flights from London to Seattle that include hotel bookings?

    Yes. In addition to deals on London to Seattle flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from London to Seattle?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from London to Seattle.

  • Can I find deals for business class flights from London to Seattle?

    Yes. Cheapflights offers flight deals from London to Seattle by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from London to Seattle?

    Currently, January is the cheapest month in which you can book a flight from London to Seattle (average of $238). Flying from London to Seattle in June is currently the most expensive (average of $387). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Traveling to a place near Seattle?

Book flights to Seattle if you plan to visit one of these locations
SeaTac
Tukwila
Tacoma
Lakewood
Ocean Shores
Lynnwood
Edmonds
Leavenworth
Renton
Lacey
Olympia
Kent
Federal Way
Cle Elum
Puyallup
Chehalis
Kirkland
Issaquah
Aberdeen
Shoreline

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Alternative routes for London to Seattle

See prices for flight routes from nearby airports that may be better suited for you.
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Top 5 airlines flying from London to Seattle

Discover the top 5 airlines that operate flights from London to Seattle. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated septiembre 15, 2025.
AirlineCheapestAverageFlexibilityOn-time
IcelandairCheapest$402Average$758FlexibilityNo cancel feeOn-time76%
British AirwaysCheapest$560Average$763FlexibilityNo cancel feeOn-time70%
Virgin AtlanticCheapest$594Average$901FlexibilityNo cancel feeOn-time72%
American AirlinesCheapest$620Average$777FlexibilityNo cancel feeOn-time71%
DeltaCheapest$621Average$820FlexibilityNo cancel feeOn-timeN/A

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